1. Technical Field
The present application relates to a method and apparatus for preparing and filling packages including pouches and containers, such as pouches and containers for food products.
2. Background Information
Background information is for informational purposes only and does not necessarily admit that subsequently mentioned information and publications are prior art.
Cleaning equipment and methods are widely known in the food and beverage industry. The technology for solid rigid containers such as bottles or the like that represent a monolithic body produced by blowing and/or deep drawing processes is fully developed. Surfaces are smooth and generally do not have grooves, folds or the like that are difficult to access.
Flexible packaging pouches however comprise a less smooth surface that can form transitions and undercuts due to the way in which they are made. Ridges, glued surfaces, and folded areas have to be accepted in the shaping of the pouches that result in areas such as grooves, folds, edges, and/or the like that are hard to reach for cleaning liquids.
For example, bags or pouches may be made in the form of a roll of individual bags or pouches that are attached at edges. In this respect, cleaning the whole roll of bags or pouches, while still wound in a roll, may be quite difficult with cleaning process of the prior art. In many cleaning methods of the prior art, it may be advantageous to unroll the wound roll of pouches or bags and to even open the bags or pouches so that most all of the surface of the bags or pouches are exposed to a cleaning material. Disposing the individual bags or pouches for cleaning may increase costs and time associated with the cleaning and filling of the bags or pouches.
Thermal treatment of the filled pouch is undesirable for many liquids and products that are commercially packaged in flexible pouches because such treatment results in impaired product quality. There is therefore a great interest in cold aseptic filling. In addition to known cleaning steps in water, vapor, or sterilizing liquids, sterilization with hydrogen peroxide is very common in industrial filling machines for beverages.
Even though this system works reliably in principle, the degree of wetting the surface to be sterilized in as short a time as possible is limited, and an increase in throughput speed at even lower germ counts cannot be achieved with this system or would require and/or desire an unjustifiably great effort and expense.
Another known method is to sterilize the packaging or film material used for producing packaging pouches and to produce these pouches in a sterile room or clean room. Some methods propose to conduct the film material in a first step through a wet cleaning station and then move the film cleaned in this way past a UV light source to achieve the desired killing of germs.
Some methods with the pre-cleaning in the first step may also be performed using a suitable liquid bath. Downstream of this first treatment step, the film is directed upwards in a shaft so that the liquid can run off, and suitable wipers of the other drying devices are positioned upstream of the UV lamp. This wet and partially mechanized cleaning step is required and/or desired to achieve substantial germ removal in a first step since UV irradiation alone is not sufficient, for example when the film material runs at high speeds. This wet mechanical treatment of the films is costly and may result in deterioration of the product due to incomplete removal of residual liquid and incomplete drying. In addition, UV irradiation does not result in the required and/or desired degree of sterilization in many cases including packaging pouches, for example when such pouches are hard to reach for UV radiation or comprise insufficiently accessible areas and/or comprise a material not transparent to UV light or with reduced UV permeability, such as multi-layer materials with one or more diffusion barrier layers.
Further, an apparatus is known for sterilizing products by high-pressure treatment, that is, applying a high pressure to sides or surfaces of the product, e.g. a process pressure in the range of 4,000 bars. This known apparatus that mainly comprises a high-pressure vessel that can be closed and to which the high process pressure can be applied, is for example intended for the treatment of food products.